How to Fix WordPress Server Error After Update

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What Is a WordPress Server Error After Update?

A WordPress server error after an update happens when you update WordPress core, a plugin, or a theme, and your site immediately crashes or displays error messages like:

  • “The site is experiencing technical difficulties”
  • “500 Internal Server Error”
  • “Fatal error: Allowed memory size exhausted”
  • “Parse error: syntax error, unexpected…”

Your site was working perfectly before the update, but the moment you clicked “Update,” everything broke. This typically occurs because the updated code is incompatible with your server environment, conflicts with other installed software, or contains bugs that weren’t present in the previous version.

The good news is that WordPress creates automatic backups during updates, making recovery straightforward in most cases.

Common Causes of Server Errors After Updates

  • PHP version incompatibility — Update requires newer PHP than your server provides
  • Plugin or theme conflict — Updated code conflicts with other installed plugins/themes
  • Corrupted update files — Update download failed or was interrupted
  • Memory limit exceeded — New version requires more PHP memory
  • Outdated plugin/theme code — Your old plugins don’t work with the new WordPress version
  • Database migration issues — Update couldn’t modify database tables properly
  • File permission problems — Server can’t write updated files
  • Missing PHP extensions — New version needs PHP modules not installed on your server

Solution 1: Access WordPress Recovery Mode

WordPress 5.2+ includes automatic recovery mode when fatal errors occur after updates.

Check your email:

  1. WordPress sends an email to your admin address with subject “Your Site is Experiencing a Technical Issue”
  2. The email contains a recovery mode link
  3. Click the link to enter recovery mode
  4. You’ll be able to access wp-admin with limited functionality

In recovery mode:

  1. Go to Plugins → Installed Plugins
  2. Deactivate the plugin that was just updated
  3. Or go to Appearance → Themes and switch to a default theme if a theme caused the issue
  4. Exit recovery mode

If you don’t receive the email, check your spam folder or use alternative methods below.

Solution 2: Restore to Previous Version via FTP

If you can’t access recovery mode, manually revert to the old version.

For WordPress Core:

  1. Download your current WordPress version from wordpress.org/download/releases
  2. Example: If you tried updating from 6.3 to 6.4 and it broke, download WordPress 6.3
  3. Extract the ZIP file on your computer
  4. Delete the wp-content folder from extracted files (important!)
  5. Via FTP, upload all remaining files to your WordPress root directory
  6. Choose “Overwrite” when prompted
  7. Test your site

For Plugins:

  1. Go to wordpress.org/plugins/[plugin-name]
  2. Click “Advanced View” → “Previous Versions”
  3. Download the last working version
  4. Via FTP, delete the current plugin folder at /wp-content/plugins/plugin-name/
  5. Upload the older version
  6. Test your site

For Themes:

  1. Find the previous theme version from your backups or the theme developer’s website
  2. Via FTP, delete /wp-content/themes/your-theme/
  3. Upload the older version
  4. Test your site

Solution 3: Disable the Updated Plugin/Theme via FTP

If you don’t have the old version, just disable the problematic component.

Via FTP:

  1. Navigate to /wp-content/plugins/ or /wp-content/themes/
  2. Find the folder for the plugin/theme you just updated
  3. Right-click and rename it (add -disabled to the end)
  4. Refresh your website

Your site should work immediately. Then:

  1. Log in to WordPress admin
  2. Find an alternative plugin/theme or wait for a bug fix release
  3. Delete the broken version completely

Solution 4: Enable WordPress Debug Mode

Identify the exact error before attempting fixes.

  1. Via FTP, open wp-config.php
  2. Find: 
    define('WP_DEBUG', false);
  3. Replace with: 
    define('WP_DEBUG', true);
define('WP_DEBUG_LOG', true);
define('WP_DEBUG_DISPLAY', false);
define('SCRIPT_DEBUG', true);
@ini_set('display_errors', 0);
  4. Save the file
  5. Check /wp-content/debug.log for error messages

The debug log shows:

  • Which file caused the error
  • What line number failed
  • The exact PHP error message

This information helps you decide whether to revert the update, increase memory, or contact support.

Solution 5: Increase PHP Memory Limit

Updates often require more memory than previous versions.

Edit wp-config.php:

Add before /* That's all, stop editing! */:

define('WP_MEMORY_LIMIT', '256M');
define('WP_MAX_MEMORY_LIMIT', '512M');

Or create/edit php.ini:

memory_limit = 256M
upload_max_filesize = 128M
post_max_size = 128M
max_execution_time = 300
max_input_time = 300
max_input_vars = 3000

Save and test. If the error was memory-related, your site should load now. You can verify this worked by checking the debug.log—memory errors will disappear.

Solution 6: Update PHP Version

Modern WordPress versions require PHP 7.4 or higher. Many updates fail on outdated PHP.

Check current PHP version:

  1. Create phpinfo.php via FTP: 
    <?php phpinfo(); ?>
  2. Visit yoursite.com/phpinfo.php
  3. Note your PHP version at the top
  4. Delete phpinfo.php after checking

Update PHP:

  1. Log in to cPanel or hosting control panel
  2. Find “PHP Version” or “MultiPHP Manager”
  3. Select your domain
  4. Choose PHP 8.0 or 8.1
  5. Apply changes
  6. Test your site

Most WordPress update errors disappear after upgrading to a current PHP version. This is especially true for plugin updates that add new features requiring modern PHP functions.

Solution 7: Repair Database After Failed Update

Updates sometimes fail halfway through database changes.

Via WordPress:

  1. Add to wp-config.php: 
    define('WP_ALLOW_REPAIR', true);
  2. Visit yoursite.com/wp-admin/maint/repair.php
  3. Click “Repair Database” or “Repair and Optimize Database”
  4. Remove the repair line from wp-config.php after completion

Via phpMyAdmin:

  1. Log in to cPanel → phpMyAdmin
  2. Select your WordPress database
  3. Check all tables
  4. Click “Check table” in the dropdown
  5. If any show errors, select them and click “Repair table”

Solution 8: Restore from Backup

If nothing else works, restore from your most recent backup.

Via hosting control panel:

  1. Log in to cPanel or hosting dashboard
  2. Find “Backups” or “Restore”
  3. Choose the most recent backup from before the update
  4. Restore your site

Via backup plugin:

If you use UpdraftPlus, BackupBuddy, or similar:

  1. Via FTP, manually reinstall the backup plugin if needed
  2. Access its restore interface at yoursite.com/wp-admin
  3. Choose the backup from before the update
  4. Click “Restore”

Manual restoration via FTP:

  1. Download your backup files
  2. Delete all files in your WordPress root (except wp-content if you want to keep media)
  3. Upload the backup files
  4. Import the backup database via phpMyAdmin

Solution 9: Re-run WordPress Update Manually

Sometimes the update just needs another attempt.

  1. Download the latest WordPress from wordpress.org
  2. Extract on your computer
  3. Delete wp-content folder from extracted files
  4. Via FTP, upload everything to your WordPress root
  5. Overwrite existing files
  6. Visit yoursite.com/wp-admin
  7. WordPress will detect the update and complete any remaining database changes

Solution 10: Check .htaccess File

Updates can corrupt .htaccess rewrite rules.

  1. Via FTP, rename .htaccess to .htaccess-backup
  2. Test your site
  3. If it works, the .htaccess was corrupted
  4. Log in to WordPress admin → Settings → Permalinks
  5. Click “Save Changes” to regenerate .htaccess

If your site still doesn’t work, rename .htaccess-backup back to .htaccess and try other solutions.

Prevention Tips for Update Errors

  • Always backup before updates — Use automatic backup plugins like UpdraftPlus
  • Test updates on staging sites first — Clone your site, test updates there, then apply to production
  • Update one thing at a time — Don’t bulk-update 15 plugins at once
  • Check compatibility before updating — Read plugin/theme changelogs for compatibility notes
  • Keep PHP version current — WordPress recommends PHP 8.0+
  • Monitor your site after updates — Check that everything works within 5 minutes
  • Use maintenance mode — Enable it before updating to prevent visitors from seeing errors
  • Read update notes — Developers often warn about breaking changes

From experience: I’ve had updates break production sites at 3 AM more times than I care to admit. Now I never update anything without a fresh backup sitting on my computer, and I test everything on staging first. Those extra 10 minutes have saved me countless hours of emergency troubleshooting.

Related: If you encounter different types of WordPress errors after updating, check How to Fix WordPress 500 Internal Server Error or How to Fix WordPress Server Error After Plugin Install for additional troubleshooting steps.

Conclusion

WordPress update errors are usually caused by incompatibility or incomplete update processes. The fastest recovery is either using WordPress’s built-in recovery mode (check your email) or manually reverting to the previous version via FTP. Most update problems come down to PHP compatibility or memory limits, both of which are quick fixes once identified. The key lesson is always backing up before updates—it transforms a potential disaster into a 5-minute inconvenience.

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